Remote-controlled flying craft, in particular for aerial photography

ABSTRACT

The invention concerns a remote-controlled flying craft, used in particular for aerial photography, comprising a nacelle ( 100 ) removably fixed to a levitating portion ( 1 ), the nacelle ( 100 ) including an elongated portion ( 101 ) which receives a propelling member ( 105 ) driving a propeller ( 106 ) mounted propelling and which extends from a fixing member ( 102 ) at the levitating part ( 1 ) to a forward protruding lower portion ( 103 ).

The invention relates to a remote-controlled flying vehicle, in particular for use in aerial photography.

It relates more particularly to flying vehicles of small size suitable for aerial photography at low speed and low altitude. This type of vehicle must be easy to use by its pilot. Unfortunately, a landing ground will not necessarily be available close to the target that is to be photographed, particularly in urban area.

The invention thus seeks to propose a particular structure for a flying vehicle that makes it easy to use, and easy to recover at the end of its mission.

For this purpose, a remote-controlled flying vehicle of the invention comprises a nacelle releasably fastened to a lift portion, the nacelle comprising an elongate portion which receives a propulsion member driving a propeller mounted as a pusher propeller and extending from a fastener member for fastening the nacelle to the lift portion down to a bottom portion that projects forwards.

The projecting portion forms a handle area for manually catching the flying vehicle in flight. Since the propeller is mounted as a pusher propeller, it does not constitute a danger for the person catching the vehicle, even if it has not been possible to stop the propulsion member.

Furthermore, the projecting portion forms a privileged zone for making contact with the ground. Such contact causes the vehicle to tilt about the projecting portion, thereby moving the propeller away from the ground and thus serving to protect it. The vehicle can thus be brought down to the ground deliberately without suffering damage, even if it cannot be caught in flight.

Finally, because the lift portion is detachable from the nacelle, these two elements can be secured to each other by fusible parts, that break in the event of too violent an impact, thereby enabling both elements to be protected.

Preferably, the nacelle includes arms extending laterally from either side of the nacelle.

The arms prevent the propeller from coming into contact with the ground in the event of the flying vehicle tilting over sideways on coming into contact with the ground.

According to a particular feature of the invention, the propulsion member is an electric motor powered by a storage battery disposed in the bottom portion of the nacelle.

The electric motor is sufficiently quiet to enable the vehicle to fly over urban areas without giving rise to significant noise nuisance. Furthermore, it can be stopped in fight while taking pictures in order to avoid vibration generated by the motor and the propeller interfering with the sharpness of the image, and it can be put back into operation very easily after the pictures have been taken.

The fact that the storage battery is in the bottom portion of the nacelle serves to offset the center of gravity of the flying vehicle towards the end of the nacelle that is remote from the lift portion. In the event of the flying vehicle being subjected to rolling or pitching oscillation due to atmospheric turbulence, the action of gravity on the nacelle naturally gives rise to a return torque tending to damp said oscillations. This offset thus increases the stability of the flying vehicle, which is particularly advantageous for a vehicle that is for taking pictures.

In a particular embodiment, the low portion of nacelle includes a housing for a camera.

Thus, advantage is taken of the presence of the low portion in order to transform it into a bay for transporting a payload. This disposition is particularly advantageous for taking pictures on a vertical axis.

The lift portion comprises a delta wing, having a frame comprising a central beam and two leading edges forming a tip. The wing extends from the central frame on either side thereof towards the leading edges, the member for securing the nacelle being connected to the central beam.

The lift portion is simple and can easily be dismantled for transport purposes.

Preferably, the leading edges are swivel-mounted to the central beam. Thus, by moving one of the leading edges towards the central beam, and/or by enabling the other leading edge to move away from the central beam, the wing can be warped so as to enable the flying vehicle to be piloted.

The lift portion advantageously includes an elevator control surface for controlling the attitude of the flying vehicle.

Other characteristics and advantages of the invention will appear more clearly in the light of the following description of a particular and non-limiting embodiment of the invention given with reference to the figures, in which:

FIG. 1 is a perspective view of the flying vehicle of the invention; and

FIG. 2 is a diagrammatic side view of the nacelle of the flying vehicle of the invention, showing how the various members of the flying vehicle are disposed.

In order to make understanding of the description easier, the terms front, back, side, vertical, up, and down as used in this document relate to the flying direction of the vehicle, the vehicle being assumed to be in a straight line flight attitude without rolling.

With reference to the figures, a flying vehicle of the invention comprises a lift portion 1 and a nacelle 100 which is releasably secured to the lift portion 1.

The lift portion 1 comprises a frame having a central beam 2 and two leading edges 2 connected to the central beam 2 in such a manner as to form a tip 4. A wing 5 extends on either side of the central beam 2 to the leading edges 3 so as to form a delta wing. The connection between each leading edge 3 and the central beam 2 is not rigid, but accommodates a certain amount of swiveling.

Each of the leading edges 3 has a fastening point 6 for a strut 7 and a sling 8. Each strut 7 is also attached to the end of an arm 114 extending laterally from the nacelle 100, while each of the slings 8 is connected to the nacelle 100, in a manner explained in greater detail below.

Each of the leading edges 3 is thus in equilibrium between the aerodynamic force to which the wing 5 is subjected, traction from the strut 7, and traction from the associated sling 8. In this case, the struts 7 are advantageously constituted by tubular rods hinged at both ends.

In a variant, the leading edges 3 may be hinged to the central beam 2 via hinges having axes that are substantially vertical, in which case the struts 7 can be omitted, the action of the slings 8 sufficing to ensure that the leading edges 3 are in equilibrium about the axes of their respective hinges.

Tension on one of the slings 8 together with relaxation on the other sling 8 causes the wing 5 to warp, enabling the flying vehicle to steer towards the side where the sling is taut.

The wing area of the wing 5 is preferably selected to be large enough to enable flying to take place at a slow speed, thereby making it easier to take pictures. Since the lift portion 5 is detachable from the nacelle 100, the flying vehicle is easy to transport, even when the area of the wing 5 is large.

An elevator control surface 9 is hinged to the central beam 2 at its end remote from the tip 4. A crank 10 secured to the elevator 9 is secured to a hinge rod 11. Traction on the rod 11 forces the flying vehicle to take on a nose-down attitude whereas thrust on the rod 11 forces the flying vehicle to take on a nose-up attitude.

The nacelle 100 comprises a body made up of an elongate portion 101 extending from a fastener member 102 for engaging the lift portion 1, down to a bottom portion 103.

The fastener member 102 is of channel section, being suitable for receiving the central beam 2 of the lift portion 1. The central beam 2 is merely pinned to the nacelle 100 by two bolts 107 that act as fuses in the event of a crash. The lift portion 1 is thus easy to detach from the nacelle 100. The connection made in this way between the central beam 2 of the lift portion 1 and the nacelle 100 is rigid.

In flight, the nacelle 100 is thus suspended beneath the lift portion 1.

The elongate portion 101 includes a pod 104 receiving an electric motor 105 which drives a propeller 106 mounted as a pusher propeller (i.e. it is mounted behind the nacelle 100). The electric motor 105 is powered by a storage battery 108 disposed in the bottom portion 103 of the nacelle 100, via a speed controller 109 controlled by a receiver 110 which communicates with a transmitter (not shown) under the control of the pilot of the flying vehicle.

The nacelle includes a servo-motor 111 controlling warping of the wing 5, and a servo-motor 112 controlling the elevator 9. In conventional manner, the servo-motor 111 actuates a lever (not shown) having the two slings 8 connected to the end thereof (detachably so as to enable the lift portion 1 to be separated from the nacelle 100), so that when the lever turns, one of the slings is put under tension and the other is relaxed. Similarly, the servo-motor 112 actuates a lever (not shown) having the rod 11 hinged (in detachable manner) to its end, so that the lever co-operates with the rod 11 and the crank 10 to constitute a deformable parallelogram.

In a variant, one of the servo-motors, or both of them, can be disposed directly on the lift portion 1. An electrical connection must then be provided between the nacelle 100 and the lift portion 1 in order to enable an electrical connection to be made between the servo-motors that are disposed on the lift portion and the receiver 110.

The bottom portion 103 of the nacelle 100 extends away from the fixing member 102 beyond the disk swept by the propeller 106, and projects forwards so as to present a toe 113 which forms a privileged point of contact with the ground in the event of a crash. Under such circumstances, the flying vehicle then tilts forwards about the toe 113 until the tip 4 of the lift portion itself comes into contact with the ground. The portions that make contact with the ground are thus minimized, so the consequences of a crash are small. The arms 114 which extend sideways from the nacelle 100 prevent direct contact between the blades of the propeller 106 and the ground in the event of the vehicle tilting sideways.

The shape of the nacelle 100 thus provides complete protection to the propeller 106 against making contact with the ground.

The toe 113 also forms a handle zone for manually catching the flying vehicle while it is in flight. Since the propeller 106 is mounted as a pusher propeller, it does not constitute a danger for the person catching the flying vehicle in flight, even if for any reason whatsoever it has not been possible to stop the electric motor 105. Catching is made even easier by the fact that during the approach stage, the flying vehicle can be constrained to fly very slowly.

The nacelle carries a camera (e.g. still camera) either in a dedicated removable casing 115 situated in the bottom portion 103 of the nacelle 100 for taking pictures looking along a vertical axis, or else, as shown in dashed lines in FIG. 2, at the end of a support 116 that is fixed to the elongate portion 101 of the nacelle 100 for taking pictures looking along an oblique axis. Picture taking can be controlled electrically, or mechanically via a dedicated servo-motor which is arranged to push against the camera button. The camera may be powered by the storage battery 108, or it may have its own power supply.

The flying vehicle is preferably arranged to carry a digital camera (not shown) associated with a real time transmitter so that the pilot can assess the position of the flying vehicle relative to the target and can assess the effect of action on the flight controls. The digital camera preferably has an optical axis that is parallel to the optical axis of the main camera.

The center of gravity of the nacelle 100 is remote from the fastener member 102 because the heavy members (the storage battery 108, the electric motor 105) are situated in the bottom portion 103, or close thereto. This downward offset of the center of gravity causes torque to be created that tends to return the flying vehicle towards a stable flight attitude (defined by the positions of the levers of the servo-motors 111 and 112) each time it departs therefrom, e.g. under the effect of atmospheric turbulence. The return torque increases with increasing offset of the center of gravity, other things remaining equal. It is thus advantageous to concentrate the heavy portions at the bottom end of the nacelle 100.

The large wing area of the lift portion 1 associated with its great stability gives the flying vehicle good gliding performance, thus making it possible to stop the electric motor 105 while taking pictures, so as to avoid the vibration generated by the electric motor 105 and the propeller 106 from having any influence on the sharpens of the pictures taken.

Although the lift portion is shown herein as being of the delta wing type with moving leading edges, any other type of lift portion could be envisaged in the ambit of the invention, for example a lift portion comprising a cantilever wing associated with a rudder and elevator tail unit.

Although the propulsion member is described herein as being an electric motor, the invention also covers the use of an internal combustion engine.

Although the payload described herein is a camera, it is clear that the payload could equally well be constituted by other types of sensor (such as, for example, thermal sensors, infrared sensors, or radars), without thereby going beyond the ambit of the invention.

Although the shape of the nacelle is adapted to be caught in the hand, it would not go beyond the ambit of the invention for the nacelle to be fitted with landing gear. 

1. A remote-controlled flying vehicle, in particular for aerial photography, the vehicle comprising a nacelle (100) releasably fastened to a lift portion (1), the nacelle (100) comprising an elongate portion (101) which receives a propulsion member (105) driving a propeller (106) mounted as a pusher propeller and extending from a fastener member (102) for fastening the nacelle to the lift portion (1) down to a bottom portion (103) that projects forwards.
 2. A remote-controlled flying vehicle according to claim 1, wherein the nacelle (100) includes arms (114) extending laterally from either side of the nacelle (100).
 3. A remote-controlled flying vehicle according to claim 1, wherein the propulsion member (105) is an electric motor powered by a storage battery (108) disposed in the bottom portion (103) of the nacelle (100).
 4. A remote-controlled flying vehicle according to claim 1, wherein the bottom portion (103) of the nacelle (100) includes a housing (115) for a camera.
 5. A remote-controlled flying vehicle according to claim 1, wherein the lift portion (1) comprises a delta wing (5).
 6. A remote-controlled flying vehicle according to claim 5, wherein the lift portion (1) includes a frame comprising a central beam (2) and two leading edges (3) forming a tip (4), the fastener member (102) of the nacelle,(100) being connected to the central beam (2).
 7. A remote-controlled flying vehicle according to claim 6, wherein the leading edges (3) are swivel-mounted to the central beam (2).
 8. A remote-controlled flying vehicle according to claim 1, wherein the lift portion (1) includes an elevator control surface (9). 